What survives is a sub-rectangular enclosure, roughly 40 metres across at its widest point, defined by an earthen bank that once enclosed a clear interior space. Only the northern and western quadrants of that bank remain legible today, and even there it is modest in scale, around a metre and a half in height. A very slight external fosse, the term for a defensive or boundary ditch dug around such a structure, can just be made out beyond the bank, though at barely a tenth of a metre deep it is more suggestion than statement.

Enclosures of this kind are scattered across the Irish landscape, and their purposes vary considerably. Some were early medieval farmsteads, known as raths or ringforts; others served as enclosures for livestock, ceremonial spaces, or places associated with local lordship. The sub-rectangular plan at Borrismore, rather than the more typical circular form, gives it a somewhat distinctive character, though it is not unique. The site sits on a broad terrace running north-west to south-east, a position that would have offered commanding views westward and south-westward across the low-lying valley plain below, a consideration that may have mattered to whoever chose this spot. The south-eastern quadrant has been cut through by a later field boundary, which accounts for much of the damage to the surviving earthwork. In the north-eastern quadrant, a broad shallow ramp may preserve the ghost of an original entrance, though the evidence is tentative.

The enclosure sits in ordinary-looking reclaimed pasture, and there is nothing on the surface to immediately announce its presence. The bank is low enough to be easily missed, and the near-vanished fosse even more so. What holds the attention, once you know what you are looking at, is the faint coherence of the remaining arc of earthwork and the sense that the terrace position was quite deliberately chosen, with that wide westward panorama still visible across the valley just as it would have been when the enclosure was in active use.